All of the A head and the EX 514 are 4.840 bore spacing on the exhaust, andmost BBC use the round ports.I have a pattern to cut those, but if you use a roundflange on the EX 514 it will not fit the port. This is a max effort pulling engine and they must fit fit the port. I will try a set of chevy squire ports. The only problem is i'am in Tn. and themotor is in Iowa. thanks

cool40 wrote:My BBC flanges fit without cutting anything. I have 2.5" tubes so no issues with covered ports.

There must have been different EX514 heads produced with different exhaust patterns because the EX514 heads I have at the shop measure a 4.900" bore spacing from port to port and the bolt spacing seems to be that way too; (the same as the original Ford Motorsport A460 heads).

I know that the TFS heads have 4.840" exhaust flange port and bolt spacing and the IDT heads have 4.900" exhaust port spacing but, have the bolt patterns at 4.840" spacing.

cool40 wrote:My BBC flanges fit without cutting anything. I have 2.5" tubes so no issues with covered ports.

There must have been different EX514 heads produced with different exhaust patterns because the EX514 heads I have at the shop measure a 4.900" bore spacing from port to port and the bolt spacing seems to be that way too; (the same as the original Ford Motorsport A460 heads).

I know that the TFS heads have 4.840" exhaust flange port and bolt spacing and the IDT heads have 4.900" exhaust port spacing but, have the bolt patterns at 4.840" spacing.

that would be why mine works,IDT heads. I never had any ex514 heads but do have old Motorsports and they are definitely different,I thought they were the only ones.